我成功地使用这段代码通过GET方法发送带有一些参数的HTTP请求
void sendRequest(String request)
{
// i.e.: request = "http://example.com/index.php?param1=a¶m2=b¶m3=c";
URL url = new URL(request);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setInstanceFollowRedirects(false);
connection.setRequestMethod("GET");
connection.setRequestProperty("Content-Type", "text/plain");
connection.setRequestProperty("charset", "utf-8");
connection.connect();
}
现在我可能需要通过POST方法发送参数(即param1, param2, param3)，因为它们非常长。
我想添加一个额外的参数，该方法(即字符串httpMethod)。
我怎样才能尽可能少地更改上面的代码，以便能够通过GET或POST发送参数?
我希望情况会有所改变
connection.setRequestMethod("GET");
to
connection.setRequestMethod("POST");
可以完成这个任务，但是参数仍然通过GET方法发送。
HttpURLConnection有任何方法可以帮助吗?
有什么有用的Java构造吗?
任何帮助都将不胜感激。
我用Boann的答案创建了一个更灵活的查询字符串构建器，支持列表和数组，就像php的http_build_query方法一样:
public static byte[] httpBuildQueryString(Map<String, Object> postsData) throws UnsupportedEncodingException {
StringBuilder postData = new StringBuilder();
for (Map.Entry<String,Object> param : postsData.entrySet()) {
if (postData.length() != 0) postData.append('&');
Object value = param.getValue();
String key = param.getKey();
if(value instanceof Object[] || value instanceof List<?>)
{
int size = value instanceof Object[] ? ((Object[])value).length : ((List<?>)value).size();
for(int i = 0; i < size; i++)
{
Object val = value instanceof Object[] ? ((Object[])value)[i] : ((List<?>)value).get(i);
if(i>0) postData.append('&');
postData.append(URLEncoder.encode(key + "[" + i + "]", "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(val), "UTF-8"));
}
}
else
{
postData.append(URLEncoder.encode(key, "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(value), "UTF-8"));
}
}
return postData.toString().getBytes("UTF-8");
}
这里我发送jsonobject作为参数//jsonobject={"name":"lucifer"，"pass":"abc"}//serverUrl = "http://192.168.100.12/testing" //主机=192.168.100.12
public static String getJson(String serverUrl,String host,String jsonobject){
StringBuilder sb = new StringBuilder();
String http = serverUrl;
HttpURLConnection urlConnection = null;
try {
URL url = new URL(http);
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
urlConnection.setUseCaches(false);
urlConnection.setConnectTimeout(50000);
urlConnection.setReadTimeout(50000);
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Host", host);
urlConnection.connect();
//You Can also Create JSONObject here
OutputStreamWriter out = new OutputStreamWriter(urlConnection.getOutputStream());
out.write(jsonobject);// here i sent the parameter
out.close();
int HttpResult = urlConnection.getResponseCode();
if (HttpResult == HttpURLConnection.HTTP_OK) {
BufferedReader br = new BufferedReader(new InputStreamReader(
urlConnection.getInputStream(), "utf-8"));
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
br.close();
Log.e("new Test", "" + sb.toString());
return sb.toString();
} else {
Log.e(" ", "" + urlConnection.getResponseMessage());
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (urlConnection != null)
urlConnection.disconnect();
}
return null;
}
GET和POST方法设置如下…两种类型的api调用1)get()和2)post()。Get()方法从API json数组中获取值& post()方法在url中的数据post中使用并获得响应。
public class HttpClientForExample {
private final String USER_AGENT = "Mozilla/5.0";
public static void main(String[] args) throws Exception {
HttpClientExample http = new HttpClientExample();
System.out.println("Testing 1 - Send Http GET request");
http.sendGet();
System.out.println("\nTesting 2 - Send Http POST request");
http.sendPost();
}
// HTTP GET request
private void sendGet() throws Exception {
String url = "http://www.google.com/search?q=developer";
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(url);
// add request header
request.addHeader("User-Agent", USER_AGENT);
HttpResponse response = client.execute(request);
System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response Code : " +
response.getStatusLine().getStatusCode());
BufferedReader rd = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()));
StringBuffer result = new StringBuffer();
String line = "";
while ((line = rd.readLine()) != null) {
result.append(line);
}
System.out.println(result.toString());
}
// HTTP POST request
private void sendPost() throws Exception {
String url = "https://selfsolve.apple.com/wcResults.do";
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(url);
// add header
post.setHeader("User-Agent", USER_AGENT);
List<NameValuePair> urlParameters = new ArrayList<NameValuePair>();
urlParameters.add(new BasicNameValuePair("sn", "C02G8416DRJM"));
urlParameters.add(new BasicNameValuePair("cn", ""));
urlParameters.add(new BasicNameValuePair("locale", ""));
urlParameters.add(new BasicNameValuePair("caller", ""));
urlParameters.add(new BasicNameValuePair("num", "12345"));
post.setEntity(new UrlEncodedFormEntity(urlParameters));
HttpResponse response = client.execute(post);
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + post.getEntity());
System.out.println("Response Code : " +
response.getStatusLine().getStatusCode());
BufferedReader rd = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()));
StringBuffer result = new StringBuffer();
String line = "";
while ((line = rd.readLine()) != null) {
result.append(line);
}
System.out.println(result.toString());
}
}
对于那些使用$_POST在php页面上接收请求的问题，因为你期望键值对:
虽然所有的答案都很有帮助，但我对实际发布哪个字符串缺乏一些基本的了解，因为在我使用的旧apache HttpClient中
new UrlEncodedFormEntity(nameValuePairs); (Java)
然后可以在php中使用$_POST获取键值对。
据我的理解，现在已经在发布之前手动构建该字符串。所以字符串应该是这样的
val data = "key1=val1&key2=val2"
而是只是把它添加到它被张贴的url(在头)。
另一种方法是使用json-string:
val data = "{\"key1\":\"val1\",\"key2\":\"val2\"}" // {"key1":"val1","key2":"val2"}
然后把它拉到php中，不需要$_POST:
$json_params = file_get_contents('php://input');
// echo_p("Data: $json_params");
$data = json_decode($json_params, true);
下面是Kotlin中的示例代码:
class TaskDownloadTest : AsyncTask<Void, Void, Void>() {
override fun doInBackground(vararg params: Void): Void? {
var urlConnection: HttpURLConnection? = null
try {
val postData = JsonObject()
postData.addProperty("key1", "val1")
postData.addProperty("key2", "val2")
// reformat json to key1=value1&key2=value2
// keeping json because I may change the php part to interpret json requests, could be a HashMap instead
val keys = postData.keySet()
var request = ""
keys.forEach { key ->
// Log.i("data", key)
request += "$key=${postData.get(key)}&"
}
request = request.replace("\"", "").removeSuffix("&")
val requestLength = request.toByteArray().size
// Warning in Android 9 you need to add a line in the application part of the manifest: android:usesCleartextTraffic="true"
// https://stackoverflow.com/questions/45940861/android-8-cleartext-http-traffic-not-permitted
val url = URL("http://10.0.2.2/getdata.php")
urlConnection = url.openConnection() as HttpURLConnection
// urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded") // apparently default
// Not sure what these are for, I do not use them
// urlConnection.setRequestProperty("Content-Type", "application/json")
// urlConnection.setRequestProperty("Key","Value")
urlConnection.readTimeout = 5000
urlConnection.connectTimeout = 5000
urlConnection.requestMethod = "POST"
urlConnection.doOutput = true
// urlConnection.doInput = true
urlConnection.useCaches = false
urlConnection.setFixedLengthStreamingMode(requestLength)
// urlConnection.setChunkedStreamingMode(0) // if you do not want to handle request length which is fine for small requests
val out = urlConnection.outputStream
val writer = BufferedWriter(
OutputStreamWriter(
out, "UTF-8"
)
)
writer.write(request)
// writer.write("{\"key1\":\"val1\",\"key2\":\"val2\"}") // {"key1":"val1","key2":"val2"} JsonFormat or just postData.toString() for $json_params=file_get_contents('php://input'); json_decode($json_params, true); in php
// writer.write("key1=val1&key2=val2") // key=value format for $_POST in php
writer.flush()
writer.close()
out.close()
val code = urlConnection.responseCode
if (code != 200) {
throw IOException("Invalid response from server: $code")
}
val rd = BufferedReader(
InputStreamReader(
urlConnection.inputStream
)
)
var line = rd.readLine()
while (line != null) {
Log.i("data", line)
line = rd.readLine()
}
} catch (e: Exception) {
e.printStackTrace()
} finally {
urlConnection?.disconnect()
}
return null
}
}
我也有同样的问题。我想通过POST发送数据。
我使用了以下代码:
URL url = new URL("http://example.com/getval.php");
Map<String,Object> params = new LinkedHashMap<>();
params.put("param1", param1);
params.put("param2", param2);
StringBuilder postData = new StringBuilder();
for (Map.Entry<String,Object> param : params.entrySet()) {
if (postData.length() != 0) postData.append('&');
postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
postData.append('=');
postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
}
String urlParameters = postData.toString();
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();
String result = "";
String line;
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line = reader.readLine()) != null) {
result += line;
}
writer.close();
reader.close()
System.out.println(result);
我使用Jsoup进行解析:
Document doc = Jsoup.parseBodyFragment(value);
Iterator<Element> opts = doc.select("option").iterator();
for (;opts.hasNext();) {
Element item = opts.next();
if (item.hasAttr("value")) {
System.out.println(item.attr("value"));
}
}
试试这个模式:
public static PricesResponse getResponse(EventRequestRaw request) {
// String urlParameters = "param1=a¶m2=b¶m3=c";
String urlParameters = Piping.serialize(request);
HttpURLConnection conn = RestClient.getPOSTConnection(endPoint, urlParameters);
PricesResponse response = null;
try {
// POST
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(urlParameters);
writer.flush();
// RESPONSE
BufferedReader reader = new BufferedReader(new InputStreamReader((conn.getInputStream()), StandardCharsets.UTF_8));
String json = Buffering.getString(reader);
response = (PricesResponse) Piping.deserialize(json, PricesResponse.class);
writer.close();
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
conn.disconnect();
System.out.println("PricesClient: " + response.toString());
return response;
}
public static HttpURLConnection getPOSTConnection(String endPoint, String urlParameters) {
return RestClient.getConnection(endPoint, "POST", urlParameters);
}
public static HttpURLConnection getConnection(String endPoint, String method, String urlParameters) {
System.out.println("ENDPOINT " + endPoint + " METHOD " + method);
HttpURLConnection conn = null;
try {
URL url = new URL(endPoint);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod(method);
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "text/plain");
} catch (IOException e) {
e.printStackTrace();
}
return conn;
}
